Americans’ support for a ban on semi-automatic guns in the U.S. has dropped eight percentage points from a year ago, when opinions were more evenly divided after the mass shooting in Las Vegas. Last year’s measure was unusually high for the trend over the past several years; the current 40% is back to within a few points of where it was between 2011 and 2016.

Credit: Gallup

In 2016, 36% supported a ban and 61% opposed one. But last year, after the Las Vegas shooting left 58 people dead and nearly 500 injured, support for a ban rose 12 points.

The current 40% support for an assault rifles ban is below the historical average of 47%. The latest data provide further evidence that public opinion typically shifts to higher support for tougher gun laws in the aftermath of a traumatic national event such as a mass shooting, but gradually reverts to prior levels as the memory of it fades.

Views of an assault weapons ban are sharply polarized politically. Since 1996, Democrats have been more supportive than Republicans of a ban on semi-automatic guns. Currently, they are more than twice as likely as Republicans to favor such a ban (56% vs. 25%). Republicans’ current reading ties with 2016 as their lowest. Thirty-eight percent of independents support a ban, continuing the recent trend in which they are more closely aligned with Republicans than with Democrats.

The highest support for a ban among each party was 50% of Republicans in 1996, 63% of Democrats in 1996, 2000 and 2017, and 63% of independents in 2000.